Then poll a register with a known, non-zero value with Modscan. If there's no communication, try swapping the driver lines on one end, sometimes one vendor's labels are the opposite of another vendor's labels. Modscan uses the indexed offset, 0033, for the register address (4)0033. Do not insert/type the leading (x) numeral, like the numeral (4) in the register address (4)0033. Modscan's Address is decimal and starts its count from one, not zero. Select the MODBUS Point Type to correspond to the data format for the slave register that you want to read, for instance, 03: HOLDING REGISTER. Reduce the Modscan 'Length' setting to 2 or 4, some small number that is easily viewed and does not take a long time to fetch. The 'Protocol Selection' defaults to RTU, but check it.Ĭonfirm that Modscan's Device ID is the same as the slave device node ID, which has to configured on the slave. The other serial settings - baud rate, word length = 8, parity, stop bits, must be the same in Modscan and the slave.

If you are using a USB/485 converter, the virtual comm port for the USB device has to match the COM port used by Modscan. In Modscan32, Connection > Connect > Connection Details dialog box Gate MODBUS enables integrations with ev- ery device supporting MODBUS RTU. Make sure that the serial communication parameters are identical on the slave and Modscan 32.

You should start with configuring the Comm port for '2 wire Modbus' (I'm presuming '2 wire' means 2 wire half duplex RS-485). RS-485 is probably some proprietary protocol. 'continuous transmission mode' is NOT Modbus.

Modbus rtu wiring diagram